Engine starter gearing



Nov. 17, 1942.

M. H. ELKIN ENGINE STARTER GEARING Filed May 9, 1941 llHlgllll INVENT OR.

MM BY A5423 4% ATTORNEY.

Patented Nov. 17, 1942 ENGINE STARTER GEARING Manuel H. Elkin, Elmira Heights, N. Y., asslgnor to Bendix "Aviation Corporation, South Bend, Ind., a corporation of Delaware Application May 9, 1941, Serial No. 392,724

7 Claims.

The present invention relates to engine starter gearing and more particularly to a deyice for assuring automatic engagement of starter gearing under all conditions.

In that type of starter gearing in which a pinion is moved automatically into engagement with an engine member when the starting motor is energized, it sometimes happens that due to congeal'ed lubricant or other causes, the movement of the pinion is delayed or prevented, thus causing a noisy mesh or even a failure to mesh on the first operation of the drive.

Various forms of detent have been suggested for holding the pinion from rotation to assure its traversal when the starting motor is energized, but unless special precautions are,taken, these have in general been subject to the disadvantage that they may be operative at inopportune times, as during a portion of the cranking period or after disengagement of the pinion but before the starting motor comes to rest.

It is an object of the present invention to provide a novel starter drive incorporating a pinion detent which is operative only during the initial period of acceleration of the starting motor.

It is another object to provide such a device in which the pinion detent is normally disengaged from the pinion but is momentarily moved into engagement therewith substantially simultaneously with the energization of the starting motor.

It is a further object of the invention to provide such a device in which the detent is retracted from the pinion after a brief time delay sufficient merely to insure initial mesh of the pinion with the engine member.

It is another object to provide such a device in which the detent cannot be re-engaged subsequent to initial actuation thereof until after the starting motor has been deenergized.

Further objects and advantages will be apparent from the following description taken in connection with the accompanying drawing. in which:

Fig. 1 is a semi-diagrammatic illustration of a preferred embodiment of the invention showing the parts in normal or idle position; and

Fig. 2 is a similar view of a second embodiment of the invention. v

In Fig. l of the drawing there is illustrated a starting motor I having a screw shaft 2 on which is provided for connecting the screw shaft 2 to the armature shaft of the starting motor, and a stop nut 6 on the screw shaft is used to limit the traversal of the pinion and thereby cause it to rotate with the screw shaft.

The starting motor I is energized from a battery 1 by means of a starting circuit comprising a lead 8. starting switch 3, and lead II attached to the starting motor, the circuit being completed through the ground.

According to the present invention means are provided for resisting rotation of the pinion 3 upon initial actuation of the starting motor in order to insure its traversal by screw shaft 2 into initial mesh with the engine gear 4. As here shown. this means is in the form of detent I2 slidably mounted in a magnet casing i3 and having a reduced stem it traversing the shank I5 of a magnetic armature iii. A spring H is interposed between the body of the detent I2 and the shank l5, and the end of.the stern i4 is riveted over at I8 to hold the spring I! in initial compression. A coil I9 mounted in the casing 83 is adapted to attract the armature I6 against the action of a releasing spring 2|. Coil I9 is grounded at one end as indicated at 22 and is energized by a control circuit comprising a lead 23 attached to the motor lead l I, armature 24, contact 25 thereon, fixed contact 26 and lead 21.

Armature 24 is actuated by an electromagnet 28 which is grounded at one end as indicated at 29 and is connected by a lead 3I and a resistor 32 to the starting motor lead I I. Resistor 32 has sufficient resistance to prevent the electromagnet 28 from being sufficiently energized to open contacts 25, 26, but said resistor passes sufficient current to hold said contacts open after they have once been broken.

Armature I6 of the detent-actuating electromagnet is provided with contacts 33 and 34 adapted to cooperate with fixed contacts 35 and 36 when the armature is in closed position. Contact 35 is connected by lead 31 to the lead 3i of electromagnet 28, while contact 36 is connected by lead 38 to the starting motor lead II so that when contacts 35 and 36 are connected through the movable contacts 33 and 34, the resistor 32 is short-circuited and the electromagnet 28 may be fully energized.

In the operation of this embodiment of the invention, closure of the starting switch 9 energizes the starting motor through the starting circuit and at the same time energizes electromagnet I9 to move the detent I2 into engagement with the periphery of the pinion 3 and thereby resist the rotation thereof. Upon initial closure of the starting switch, the electromagnet II is energized by current passing through the resistor 32, but this current is insufllcient to open contacts 25, 26. When the contacts ll, 35, and I4,'

36 are closed by the energization of the coil II, the resistor 32 is bridged and coil 28 is fully energized whereby contact 25 is moved out of engagement with contact 26, and coil I9 is thereupon deenergized. The detent I2 is thereupon moved out of engagement with the pinion I by the reaction spring 2!, the detent having served its purpose of preventing rotation of the pinion during the initial rotation of the starting motor, thus insuring entry of the pinion teeth into the teeth the engine gear.

When coil I9 is deenergized, the bridging contacts 33, 35, 34 and 36 are opened, but the contacts 25, 26 are held open by the coil 28 as energized by current traversing the resistor 32 so that reactuation of the detent is prevented. This condition prevails until the starting switch is opened, whereupon the parts return to their normal positions as illustrated preparatory to the next starting operation.

In the embodiment of the invention illustrated in Fig. 2, the starting motor and gearing are the same as in the embodiment first described and are similarly numbered. In this case, however, an electrically operated starting switch 38 is used to connect the starting motor to the battery, and this switch is energized by a control circuit comprising a lead 4|, manual switch 42, lead 43, holding resistor 44 and lead 45. The holding resistor is adapted to be bridged by a switch 48 arranged to be closed by a solenoid 4'1 which also actuates a detent 48 for the pinion 3. Solenoid 41 is connected at one end by a lead 49 to the control circuit lead 43 and at its other end by a lead 5| to a magnetic switch 52 which is grounded at 53. Switch 52 is normally closed but is adapted to be opened by a solenoid 54 connected at one end by a lead 55 to the starting circuit lead H and grounded at its other end as indicated at 58. The action of the coil 54 in opening the switch 52 is preferably delayed by any of the usual methods of delaying the response of a magnetic relay such as by including a copper sheath 5! or shorted copper coil in the path of flux of said magnet. This delay need only be suflicient to insure that the detent remains operative until the pinion has traversed into initial engagement with the engine flywheel, which is of course only a very short time interval. It will be understood that the electromagnetic detent and switch in this embodiment of the invention may take the form illustrated in Fig. 1, but this mechanism is merely diagrammatically illustrated in Fig. 2 in order to simplify the showing,

In the operation of this second embodiment of the invention closure of the manual switch 42 completes the control circuit for the starting switch 39 through the holding resistor 44 which prevents immediate closure of the starting switch. At the same time, a circuit is completed through the detent solenoid 41 and magnetic switch 52 to the ground whereby the detent 48 is moved into engagement with the pinion 3, thus resisting the rotation thereof, and bridging switch 45 is closed. This causes full energization of the starting switch 39 which thereupon closes, thereby energizing the starting motor I and also energizing the solenoid 54 to open the switch 52. The detent coil 41 is thus deenergized, the detent withdrawn, and the bridging switch 46 opened,

rent traversing the resistor 44, the cranking operatlon proceeds until the engine starts. The manual switch 42 is then opened, and the parts thereby permitted to return to their idle positions.

Although but two embodiments of the invention have been shown and described in detail, it wil be understood that other embodiments are possible and various changes may be made in the design and arrangement of the parts without departing from the spirit of the invention as defined in the claims appended thereto.

What is claimed is:

1. In an engine starter, a starting motor, a pinion actuated thereby to engage and rotate a member of an engine to be started, a detent for opposing rotation of the pinion, means for causing the detent to engage the pinion when the starting motor is energized, and means causing release of the detent after a time delay and preventing reactuation oi the detent.

2. In an engine starter, a starting motor, a pinion actuated thereby to engage and rotate a member of an engine to be started, a detent for opposing rotation of the pinion, electromagnetic means energized simultaneously with the starting motor for moving the detent into engagement with the pinion, and electromagnetic means energized concurrently with the starting motor for thereafter deenergizing th detent-actuating means and preventing reactuation thereof.

3. In an engine starter, a power shaft, a pinion threaded thereon for movement into and out of engagement with a member of an engine to be started, a starting circuit including a starting switch, an electromagnetic detent for the pinion energized by closure of the starting switch, means energized by actuation of the detent for deenergizing the detent, and holding means for the deenergizing means under the control of the starting switch.

4. In an engine starter, a power shaft, a pinion threaded thereon for movement into and out of engagement with a member of an engine to be started, a starting circuit including a magnetic starting switch, a magnetic detent for the pinion, a control circuit for the detent including a manual switch and a set of normally closed contacts, a control circuit for the magnetic starting switch including said manual switch and a switch closed by actuation of the detent, holding means for the detent switch, and an electromagnet controlled by the starting switch for opening said but since the starting switch is held closed by curcontacts.

5. In combination with a starting motor, a screw shaft rotated thereby and a pinion having a threaded connection with the screw shaft for movement into and out of engagement with a member of an engine to be started, an electromagnetic detent for opposing rotation of the pinion to assure its traversal into mesh with the engine member, a starting circuit including a starting switch, a control circuit for the magnetic detent including a set of normally closed contacts, and electromagnetic means under the control of the starting switch for opening said contacts.

6. In an engine starter, a starting motor, a pinion actuated thereby to engage and rotate a member of an engine to be started, a detent for opposing rotation of the pinion, means for causing the detent to momentarily engage the pinion upon actuation of the starting motor, means energized in response to movement of the detent to operative position for releasing the detent and preventing re-actuation thereof, and means for deenergizing the releasing means when the starting motor is deenergized.

7. In combination with a starting motor, a screw shaft rotated thereby and a pinion having a threaded connection with the screw shaft for movement into and out of engagement with a member of an engine to be started, an electromagnetic detent for opposing rotation of the pinion to assure its traversal into mesh with the engine member, a starting circuit including a starting switch, and means for momentarily actuating the magnetic detent including a control circuit having a set of normally closed contacts and a slow-acting coil energized by closure of the starting switch for opening said contacts after a predetermined time interval.

MANUEL H. ELKIN. 

